Characterizing the bacterial surface profiles of menstrual cups and their association with user characteristics and vaginal microbiomes in an adolescent cohort from western Kenya.

Background: Menstrual cups are increasingly promoted in low-resource settings as long-lasting and cost-effective menstrual hygiene solutions. However, no studies have been done among cup users to characterize the bacterial communities found on cups with long-term use when stored. This study sought to comprehensively characterize the bacterial surface profile of the menstrual cup, identify factors associated with putative pathogens, and quantify the vaginal microbiome as potential source for menstrual cup bacterial communities. Methods: , coliform bacteria), and factors associated with vaginal microbiome as potential source environment to bacterial surface profile of the menstrual cup, estimated via fast expectation-maximization for microbial source tracking (FEAST). Results: On average, 25.1% of cup microbiota originated from the vagina, with lower contributions among older participants and those with damaged cups. No serious adverse events related to the menstrual cup were observed in the cohort. Conclusions: Interventions focused on improved cleaning and storage tools and methods, and access to clean water and sanitation infrastructure are required to maximize safety of menstrual cup use in low-resource settings.